10 



CONNECTICUT GEOL. AND NAT. HIST. SURVEY. 



[Bull. 



the larva has legs, and resembles a caterpillar even to the habit 

 of providing food for itself. The pupa is comparable with the 

 chrysalis stage in butterflies. The stages in the life of the im- 

 ported Currant Worm (Pteronidea ribesi) are shown in Figs. 3-7. 



Two of the most striking peculiarities of the Hymenoptera 

 are that the front wings are held to the hind wings by a series 

 of hooks on the front edge of the hind wings that fit into a fold 

 on the hind margin of the front wings ; and that as a rule the 

 seeming hind segment of the thorax, erroneously called the meta- 

 thorax, is in reality the first segment of the abdomen transferred 

 to and fused with the real hind segment of the thorax so as to 

 appear as part of the thorax. 



Other peculiarities are the inconstant number of joints in the 

 feelers or antennae in the sawflies, horntails, Ichneumon flies, 

 four-winged gall-flies, Chalcis flies, Serphus flies, and ants, as 

 compared with the wasps and bees, in which the male and female, 

 almost without exception, have thirteen and twelve joints re- 

 spectively. Moreover, in the wasps and bees there are usually 

 six abdominal segments in the female and seven in the male, 

 which is not the rule in all the other groups. In the sawflies 

 the female is provided with two saw-like appendages at the tip 

 of the abdomen. These are used in making slits into the plant 

 preparatory to laying eggs. The female horntail has the tip 

 of the abdomen developed into a boring apparatus used in laying 

 its eggs. The female of the Ichneumon flies has an egg-laying 

 tube supported on each side by an appendage, usually of the 

 same length as the tube. This arrangement enables the insect 

 to pierce substances and deposit its eggs to a depth that is in 

 some species greater than the length of the abdomen. The female 

 of the four-winged gall-fly, Chalcis fly, and Serphus fly, is equip- 

 ped in much the same way as the preceding except that the ovi- 

 positor is more commonly shorter or entirely hidden. In the ants 

 a sting begins to show in the females and workers, while in the 

 wasps and bees both female and worker are supplied with a sting 

 at the tip of the abdomen. This sting is connected with a poison 

 gland, and, when exercised by a species 10 mm. or more in length, 

 is capable of inflicting a painful and sometimes severe wound. 

 The poison, however, can be counteracted by the prompt adminis- 

 tration of the chemical antidote, ammonia water. 



